Oceans and Plate Tectonics - Vocabulary Flashcards

Vocabulary flashcards covering key terms from the lecture notes on oceans, plate tectonics, sediments, climate, and related concepts.

Arctic Ocean

The northernmost and smallest of the world's oceans.

Atlantic Ocean

The ocean between the Americas and the continents of Europe and Africa.

Pacific Ocean

The largest ocean on Earth.

Indian Ocean

The ocean bordered by Africa, Asia, Australia, and the Indian subcontinent.

Southern Ocean

The ocean surrounding Antarctica, defined by circumpolar waters.

Equator

0° latitude; the imaginary line around the middle of Earth.

Continental Drift

Theory that continents have moved slowly over Earth's surface.

Pangaea

A supercontinent that existed about 225 million years ago, comprising all Earth's land.

Laurasia

Northern part of Pangaea that later split into North America, Europe, and Asia.

Gondwana

Southern part of Pangaea that split into Africa, South America, Antarctica, India, and Australia.

Lithosphere

Rigid outer layer of the Earth, including the crust and upper mantle.

Asthenosphere

Semi-fluid layer beneath the lithosphere that allows plate movement.

Crust

Earth's outermost layer; oceanic crust is thin and dense, continental crust is thick and less dense.

Mantle

Layer between the crust and core; includes upper and lower portions.

Outer Core

Liquid iron-nickel layer that generates Earth's magnetic field.

Inner Core

Solid iron-nickel sphere at Earth's center.

Tectonic Plate

Large, rigid slab of the lithosphere that moves slowly over the mantle.

Mid-Ocean Ridge

Undersea mountain chain where new ocean floor forms by seafloor spreading.

Subduction Zone

Region where one plate sinks beneath another into the mantle.

Trench

Deep, elongated depression at a subduction zone.

Slab Pull

Gravitational pull of a sinking plate helping drive plate motion.

Ridge Push

Force from elevated new lithosphere at ridges pushing plates apart.

Convection Current (Mantle)

Circulation in the mantle that drives plate tectonics.

Hotspot

Stable plume of hot mantle material that creates volcanic chains as plates move over it.

Volcanic Island

Island formed by volcanic activity on the seafloor, often above a hotspot.

Seamount

Underwater volcanic hill or mountain that does not reach the surface.

Island Arc

Curved chain of volcanic islands formed above a subduction zone.

Paleomagnetism

Study of ancient magnetic fields preserved in rocks, used as evidence for plate movement.

Magnetic Reversal

Switching of Earth's magnetic polarity from normal to reversed or vice versa.

Continental Margin

Coastline region where a continent meets the ocean, including shelf, slope, and rise.

Continental Shelf

Flat, shallow extension of a continent before the shelf break.

Continental Slope

Steep descent from the shelf to the deep ocean.

Abyssal Plain

Flat, deep-ocean floor region beyond continental margins.

Guyot

Flat-topped submarine volcano or seamount.

Hydrothermal Vent

Undersea vent releasing mineral-rich, heated water from the seafloor.

Calcareous Ooze

Biogenic sediment composed mainly of calcium carbonate from marine organisms.

Siliceous Ooze

Biogenic sediment composed mainly of silica from microscopic organisms.

Lithogenous Sediment

Sediment derived from weathered rocks brought to the ocean from land.

Biogenous Sediment

Sediment produced by biological activity in the ocean.

Microfossils

Very small fossils used to study past environments and plate motion.

Glacial-Interglacial Cycles

Alternating cold (glacial) and warm (interglacial) periods affecting sea level.

Sea Level Change

Variations in sea level over time due to climate and glacial cycles.

Magnetic Evidence

Magnetic signatures in rocks that support seafloor spreading and plate tectonics.